[net-next-2.6.git] / drivers / leds / led-triggers.c

/*
 * LED Triggers Core
 *
 * Copyright 2005-2007 Openedhand Ltd.
 *
 * Author: Richard Purdie <rpurdie@openedhand.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
#include "leds.h"

/*
 * Nests outside led_cdev->trigger_lock
 */
static DECLARE_RWSEM(triggers_list_lock);
static LIST_HEAD(trigger_list);

 /* Used by LED Class */

ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	char trigger_name[TRIG_NAME_MAX];
	struct led_trigger *trig;
	size_t len;

	trigger_name[sizeof(trigger_name) - 1] = '\0';
	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	len = strlen(trigger_name);

	if (len && trigger_name[len - 1] == '\n')
		trigger_name[len - 1] = '\0';

	if (!strcmp(trigger_name, "none")) {
		led_trigger_remove(led_cdev);
		return count;
	}

	down_read(&triggers_list_lock);
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(trigger_name, trig->name)) {
			down_write(&led_cdev->trigger_lock);
			led_trigger_set(led_cdev, trig);
			up_write(&led_cdev->trigger_lock);

			up_read(&triggers_list_lock);
			return count;
		}
	}
	up_read(&triggers_list_lock);

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(led_trigger_store);

ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_trigger *trig;
	int len = 0;

	down_read(&triggers_list_lock);
	down_read(&led_cdev->trigger_lock);

	if (!led_cdev->trigger)
		len += sprintf(buf+len, "[none] ");
	else
		len += sprintf(buf+len, "none ");

	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
							trig->name))
			len += sprintf(buf+len, "[%s] ", trig->name);
		else
			len += sprintf(buf+len, "%s ", trig->name);
	}
	up_read(&led_cdev->trigger_lock);
	up_read(&triggers_list_lock);

	len += sprintf(len+buf, "\n");
	return len;
}
EXPORT_SYMBOL_GPL(led_trigger_show);

/* Caller must ensure led_cdev->trigger_lock held */
void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
{
	unsigned long flags;

	/* Remove any existing trigger */
	if (led_cdev->trigger) {
		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
		list_del(&led_cdev->trig_list);
		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
			flags);
		if (led_cdev->trigger->deactivate)
			led_cdev->trigger->deactivate(led_cdev);
		led_cdev->trigger = NULL;
		led_set_brightness(led_cdev, LED_OFF);
	}
	if (trigger) {
		write_lock_irqsave(&trigger->leddev_list_lock, flags);
		list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
		write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
		led_cdev->trigger = trigger;
		if (trigger->activate)
			trigger->activate(led_cdev);
	}
}
EXPORT_SYMBOL_GPL(led_trigger_set);

void led_trigger_remove(struct led_classdev *led_cdev)
{
	down_write(&led_cdev->trigger_lock);
	led_trigger_set(led_cdev, NULL);
	up_write(&led_cdev->trigger_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_remove);

void led_trigger_set_default(struct led_classdev *led_cdev)
{
	struct led_trigger *trig;

	if (!led_cdev->default_trigger)
		return;

	down_read(&triggers_list_lock);
	down_write(&led_cdev->trigger_lock);
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(led_cdev->default_trigger, trig->name))
			led_trigger_set(led_cdev, trig);
	}
	up_write(&led_cdev->trigger_lock);
	up_read(&triggers_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_set_default);

/* LED Trigger Interface */

int led_trigger_register(struct led_trigger *trigger)
{
	struct led_classdev *led_cdev;
	struct led_trigger *trig;

	rwlock_init(&trigger->leddev_list_lock);
	INIT_LIST_HEAD(&trigger->led_cdevs);

	down_write(&triggers_list_lock);
	/* Make sure the trigger's name isn't already in use */
	list_for_each_entry(trig, &trigger_list, next_trig) {
		if (!strcmp(trig->name, trigger->name)) {
			up_write(&triggers_list_lock);
			return -EEXIST;
		}
	}
	/* Add to the list of led triggers */
	list_add_tail(&trigger->next_trig, &trigger_list);
	up_write(&triggers_list_lock);

	/* Register with any LEDs that have this as a default trigger */
	down_read(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		down_write(&led_cdev->trigger_lock);
		if (!led_cdev->trigger && led_cdev->default_trigger &&
			    !strcmp(led_cdev->default_trigger, trigger->name))
			led_trigger_set(led_cdev, trigger);
		up_write(&led_cdev->trigger_lock);
	}
	up_read(&leds_list_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(led_trigger_register);

void led_trigger_unregister(struct led_trigger *trigger)
{
	struct led_classdev *led_cdev;

	/* Remove from the list of led triggers */
	down_write(&triggers_list_lock);
	list_del(&trigger->next_trig);
	up_write(&triggers_list_lock);

	/* Remove anyone actively using this trigger */
	down_read(&leds_list_lock);
	list_for_each_entry(led_cdev, &leds_list, node) {
		down_write(&led_cdev->trigger_lock);
		if (led_cdev->trigger == trigger)
			led_trigger_set(led_cdev, NULL);
		up_write(&led_cdev->trigger_lock);
	}
	up_read(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister);

/* Simple LED Tigger Interface */

void led_trigger_event(struct led_trigger *trigger,
			enum led_brightness brightness)
{
	struct list_head *entry;

	if (!trigger)
		return;

	read_lock(&trigger->leddev_list_lock);
	list_for_each(entry, &trigger->led_cdevs) {
		struct led_classdev *led_cdev;

		led_cdev = list_entry(entry, struct led_classdev, trig_list);
		led_set_brightness(led_cdev, brightness);
	}
	read_unlock(&trigger->leddev_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_event);

void led_trigger_register_simple(const char *name, struct led_trigger **tp)
{
	struct led_trigger *trigger;
	int err;

	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);

	if (trigger) {
		trigger->name = name;
		err = led_trigger_register(trigger);
		if (err < 0)
			printk(KERN_WARNING "LED trigger %s failed to register"
				" (%d)\n", name, err);
	} else
		printk(KERN_WARNING "LED trigger %s failed to register"
			" (no memory)\n", name);

	*tp = trigger;
}
EXPORT_SYMBOL_GPL(led_trigger_register_simple);

void led_trigger_unregister_simple(struct led_trigger *trigger)
{
	if (trigger)
		led_trigger_unregister(trigger);
	kfree(trigger);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);

MODULE_AUTHOR("Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Triggers Core");
Commit	Line	Data
c3bc9956 RP	1	/*
	2	* LED Triggers Core
	3	*
f8a7c6fe	4	* Copyright 2005-2007 Openedhand Ltd.
c3bc9956 RP	5	*
	6	* Author: Richard Purdie <rpurdie@openedhand.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
c3bc9956 RP	14	#include <linux/module.h>
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
	17	#include <linux/list.h>
	18	#include <linux/spinlock.h>
	19	#include <linux/device.h>
	20	#include <linux/sysdev.h>
	21	#include <linux/timer.h>
dc47206e	22	#include <linux/rwsem.h>
c3bc9956 RP	23	#include <linux/leds.h>
	24	#include "leds.h"
	25
	26	/*
	27	* Nests outside led_cdev->trigger_lock
	28	*/
dc47206e	29	static DECLARE_RWSEM(triggers_list_lock);
c3bc9956 RP	30	static LIST_HEAD(trigger_list);
c3bc9956 RP	31
4d404fd5 NM	32	/* Used by LED Class */
4d404fd5 NM	33
f8a7c6fe RP	34	ssize_t led_trigger_store(struct device dev, struct device_attribute attr,
f8a7c6fe RP	35	const char *buf, size_t count)
c3bc9956	36	{
f8a7c6fe	37	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	38	char trigger_name[TRIG_NAME_MAX];
	39	struct led_trigger *trig;
	40	size_t len;
	41
	42	trigger_name[sizeof(trigger_name) - 1] = '\0';
	43	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
	44	len = strlen(trigger_name);
	45
	46	if (len && trigger_name[len - 1] == '\n')
	47	trigger_name[len - 1] = '\0';
	48
	49	if (!strcmp(trigger_name, "none")) {
0013b23d	50	led_trigger_remove(led_cdev);
c3bc9956 RP	51	return count;
	52	}
	53
dc47206e	54	down_read(&triggers_list_lock);
c3bc9956 RP	55	list_for_each_entry(trig, &trigger_list, next_trig) {
c3bc9956 RP	56	if (!strcmp(trigger_name, trig->name)) {
dc47206e	57	down_write(&led_cdev->trigger_lock);
c3bc9956	58	led_trigger_set(led_cdev, trig);
dc47206e	59	up_write(&led_cdev->trigger_lock);
c3bc9956	60
dc47206e	61	up_read(&triggers_list_lock);
c3bc9956 RP	62	return count;
	63	}
	64	}
dc47206e	65	up_read(&triggers_list_lock);
c3bc9956 RP	66
	67	return -EINVAL;
	68	}
4d404fd5	69	EXPORT_SYMBOL_GPL(led_trigger_store);
c3bc9956	70
f8a7c6fe RP	71	ssize_t led_trigger_show(struct device dev, struct device_attribute attr,
f8a7c6fe RP	72	char *buf)
c3bc9956	73	{
f8a7c6fe	74	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 RP	75	struct led_trigger *trig;
	76	int len = 0;
	77
dc47206e RP	78	down_read(&triggers_list_lock);
dc47206e RP	79	down_read(&led_cdev->trigger_lock);
c3bc9956 RP	80
	81	if (!led_cdev->trigger)
	82	len += sprintf(buf+len, "[none] ");
	83	else
	84	len += sprintf(buf+len, "none ");
	85
	86	list_for_each_entry(trig, &trigger_list, next_trig) {
	87	if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
	88	trig->name))
	89	len += sprintf(buf+len, "[%s] ", trig->name);
	90	else
	91	len += sprintf(buf+len, "%s ", trig->name);
	92	}
dc47206e RP	93	up_read(&led_cdev->trigger_lock);
dc47206e RP	94	up_read(&triggers_list_lock);
c3bc9956 RP	95
	96	len += sprintf(len+buf, "\n");
	97	return len;
	98	}
4d404fd5	99	EXPORT_SYMBOL_GPL(led_trigger_show);
c3bc9956 RP	100
	101	/* Caller must ensure led_cdev->trigger_lock held */
	102	void led_trigger_set(struct led_classdev led_cdev, struct led_trigger trigger)
	103	{
	104	unsigned long flags;
	105
	106	/* Remove any existing trigger */
	107	if (led_cdev->trigger) {
	108	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
	109	list_del(&led_cdev->trig_list);
4d404fd5 NM	110	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
4d404fd5 NM	111	flags);
c3bc9956 RP	112	if (led_cdev->trigger->deactivate)
c3bc9956 RP	113	led_cdev->trigger->deactivate(led_cdev);
fe3025b5	114	led_cdev->trigger = NULL;
e3e5fc91	115	led_set_brightness(led_cdev, LED_OFF);
c3bc9956 RP	116	}
	117	if (trigger) {
	118	write_lock_irqsave(&trigger->leddev_list_lock, flags);
	119	list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
	120	write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
fe3025b5	121	led_cdev->trigger = trigger;
c3bc9956 RP	122	if (trigger->activate)
	123	trigger->activate(led_cdev);
	124	}
c3bc9956	125	}
4d404fd5	126	EXPORT_SYMBOL_GPL(led_trigger_set);
c3bc9956	127
0013b23d NM	128	void led_trigger_remove(struct led_classdev *led_cdev)
	129	{
	130	down_write(&led_cdev->trigger_lock);
	131	led_trigger_set(led_cdev, NULL);
	132	up_write(&led_cdev->trigger_lock);
	133	}
4d404fd5	134	EXPORT_SYMBOL_GPL(led_trigger_remove);
0013b23d	135
c3bc9956 RP	136	void led_trigger_set_default(struct led_classdev *led_cdev)
	137	{
	138	struct led_trigger *trig;
	139
	140	if (!led_cdev->default_trigger)
	141	return;
	142
dc47206e RP	143	down_read(&triggers_list_lock);
dc47206e RP	144	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	145	list_for_each_entry(trig, &trigger_list, next_trig) {
	146	if (!strcmp(led_cdev->default_trigger, trig->name))
	147	led_trigger_set(led_cdev, trig);
	148	}
dc47206e RP	149	up_write(&led_cdev->trigger_lock);
dc47206e RP	150	up_read(&triggers_list_lock);
c3bc9956	151	}
4d404fd5 NM	152	EXPORT_SYMBOL_GPL(led_trigger_set_default);
	153
	154	/* LED Trigger Interface */
c3bc9956 RP	155
	156	int led_trigger_register(struct led_trigger *trigger)
	157	{
	158	struct led_classdev *led_cdev;
700c6ea2	159	struct led_trigger *trig;
c3bc9956 RP	160
	161	rwlock_init(&trigger->leddev_list_lock);
	162	INIT_LIST_HEAD(&trigger->led_cdevs);
	163
dc47206e	164	down_write(&triggers_list_lock);
700c6ea2 AN	165	/* Make sure the trigger's name isn't already in use */
	166	list_for_each_entry(trig, &trigger_list, next_trig) {
	167	if (!strcmp(trig->name, trigger->name)) {
	168	up_write(&triggers_list_lock);
	169	return -EEXIST;
	170	}
	171	}
	172	/* Add to the list of led triggers */
c3bc9956	173	list_add_tail(&trigger->next_trig, &trigger_list);
dc47206e	174	up_write(&triggers_list_lock);
c3bc9956 RP	175
c3bc9956 RP	176	/* Register with any LEDs that have this as a default trigger */
72f8da32	177	down_read(&leds_list_lock);
c3bc9956	178	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	179	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	180	if (!led_cdev->trigger && led_cdev->default_trigger &&
	181	!strcmp(led_cdev->default_trigger, trigger->name))
	182	led_trigger_set(led_cdev, trigger);
dc47206e	183	up_write(&led_cdev->trigger_lock);
c3bc9956	184	}
72f8da32	185	up_read(&leds_list_lock);
c3bc9956 RP	186
	187	return 0;
	188	}
4d404fd5	189	EXPORT_SYMBOL_GPL(led_trigger_register);
c3bc9956 RP	190
	191	void led_trigger_unregister(struct led_trigger *trigger)
	192	{
	193	struct led_classdev *led_cdev;
	194
	195	/* Remove from the list of led triggers */
dc47206e	196	down_write(&triggers_list_lock);
c3bc9956	197	list_del(&trigger->next_trig);
dc47206e	198	up_write(&triggers_list_lock);
c3bc9956 RP	199
c3bc9956 RP	200	/* Remove anyone actively using this trigger */
72f8da32	201	down_read(&leds_list_lock);
c3bc9956	202	list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e	203	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	204	if (led_cdev->trigger == trigger)
c3bc9956 RP	205	led_trigger_set(led_cdev, NULL);
dc47206e	206	up_write(&led_cdev->trigger_lock);
c3bc9956	207	}
72f8da32	208	up_read(&leds_list_lock);
c3bc9956	209	}
4d404fd5	210	EXPORT_SYMBOL_GPL(led_trigger_unregister);
c3bc9956	211
4d404fd5 NM	212	/* Simple LED Tigger Interface */
	213
	214	void led_trigger_event(struct led_trigger *trigger,
	215	enum led_brightness brightness)
c3bc9956	216	{
4d404fd5 NM	217	struct list_head *entry;
	218
	219	if (!trigger)
	220	return;
	221
	222	read_lock(&trigger->leddev_list_lock);
	223	list_for_each(entry, &trigger->led_cdevs) {
	224	struct led_classdev *led_cdev;
	225
	226	led_cdev = list_entry(entry, struct led_classdev, trig_list);
	227	led_set_brightness(led_cdev, brightness);
	228	}
	229	read_unlock(&trigger->leddev_list_lock);
c3bc9956	230	}
4d404fd5	231	EXPORT_SYMBOL_GPL(led_trigger_event);
c3bc9956	232
4d404fd5 NM	233	void led_trigger_register_simple(const char name, struct led_trigger *tp)
	234	{
	235	struct led_trigger *trigger;
	236	int err;
c3bc9956	237
4d404fd5	238	trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
c3bc9956	239
4d404fd5 NM	240	if (trigger) {
	241	trigger->name = name;
	242	err = led_trigger_register(trigger);
	243	if (err < 0)
	244	printk(KERN_WARNING "LED trigger %s failed to register"
	245	" (%d)\n", name, err);
	246	} else
	247	printk(KERN_WARNING "LED trigger %s failed to register"
	248	" (no memory)\n", name);
	249
	250	*tp = trigger;
	251	}
c3bc9956	252	EXPORT_SYMBOL_GPL(led_trigger_register_simple);
4d404fd5 NM	253
	254	void led_trigger_unregister_simple(struct led_trigger *trigger)
	255	{
	256	if (trigger)
	257	led_trigger_unregister(trigger);
	258	kfree(trigger);
	259	}
c3bc9956	260	EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
c3bc9956 RP	261
	262	MODULE_AUTHOR("Richard Purdie");
	263	MODULE_LICENSE("GPL");
	264	MODULE_DESCRIPTION("LED Triggers Core");